There were once such devices for cell phones on sale called a blinker. When you receive a call or SMS or when you call, the blinker LED starts blinking, signaling a call. The blinker can be with or without power supply. The LM358 microcircuit shows a diagram of a device powered by two disk elements. It responds to a call from a distance of about 30-40 cm from the phone, but it should be taken into account that the device only works with operators whose signal we hear as interference on the speakers. This is exactly the signal that the blinker will work on. The current consumption in standby mode is about 700 μA
The flasher can be made without a power supply. For this, you will need two modern RF Schottky diodes and a flat LED, which is used in LED lamps and can operate at low current. There are two antennas, the second one I did not show in the diagram, it is connected to one of the LED terminals. The length of the antennas is about 3 cm, it should be selected experimentally, based on the maximum glow of the LED during a conversation. The device is attached to the phone. The operation and appearance of the device can be seen in the video
No comments:
Post a Comment